Core standard: GB/T 8446.2-2022 "Heat sinks for power semiconductor devices - Part 2: Measurement methods for thermal resistance 

and flow resistance" * *, the only national standard for power semiconductor heat sinks (air-cooled/self cooled/water-cooled, 

extruded/cast/heat pipe heat sinks) in China that simultaneously specifies joint testing of thermal resistance and flow resistance

Thermal resistance: steady-state heat transfer\ (R=\Delta T/P\)， Unit K/W; Flow resistance (pressure difference loss): The pressure

 difference between the inlet and outlet of a radiator that fluid flows through, expressed in Pa, typically measured by the P-Q pressure difference flow curve